Improvement in propellers



G. L. McCAY. Improvement in Propellers.

Patented .Ian. 30, 1872} GEORGE L. MCOAY, OF LINWOOD STATION, PENNSYLVANIA.

IMPROVEMENT IN PROPELLERS.

Specification forming part of Letters Patent No. 123,274, dated January 30, 1872.

Specification describing an Improvement in Propellers, invented by GEORGE L. MOGAY, of Linwood Station, Delaware county, Pennsylvania.

Improvement in Propellers.

My invention relates to propellers in which the blades are secured separately to the hub; and consists in the peculiar manner of securing the blades, too fully described hereafter to need preliminary explanation, whereby the removal of any one or more damaged blades and the insertion of new ones may be readily efl'ected.

Figure 1 is a front view, partly in section, of my improved propeller; Fig. 2, a plan View; Fig. 3, a transverse section of the hub or vane of the propeller drawn to an enlarged scale; and Fig. 4, a perspective view illustrating the detailed construction of my invention.

The-blades A A of the propeller may be of any shape or pitch which circumstances may suggest, but they are secured to the hub in the peculiar manner which I will now proceed to describe. B is the hub secured to the propeller-shaft D, and this hub has an enlarged central portion, a, and at the opposite ends of the latter portions 1) 1) reduced in diameter. In the enlarged portion aof the hub are cut as many dovetailed grooves (1 as there are blades, four in the present instance, and into each groove fits the dovetailed rib e of the flange E of one of the blades. These flanges E are such that when all the blades are adjusted. to their places on the hub the said flanges will fit snugly to and completely incase the enlarged portion a of the hub, the flanges of one blade touching or nearly touching that of the adjoining blade, as seen in Fig. 1. A collar, G, is fitted to each reduced portion 1) of the hub, and each collar abuts against a shoulder, y, formed on the hub where the enlarged portion ofthe same meets the reduced portion, the collar also bearing against the ends of the flanges of the blades, and having an annular lip, h, which overlaps the recessed ends .00 of the said flanges. Each collar is confined to the shaft D, in the present instance, by a transverse pin, it; but it should be understood that I do not desire to restrict myself to this precise mode of securing the collars to the shaft.

It will be seen that the annular lips h' of the ,collars aid the dovetailed ribs 6 in resisting all tendency of the blades to be detached in a radial direction from the hub, while the proper transverse position of the blade is insured by the collars G G, as shown in Fig. 3. As regards the resistance of any tendency of the blades to twist on the hub, reliance is not placed on the dovetailed ribs alone, as the flanges of the blades are fitted snugly to the hub and are confined thereto by the collars. The dovetailed ribs are consequently relieved to a great extent from strains imparted by the tendency of the blades to turn. The blades are, in fact, as much a part of the hub as if cast with the same, and yet any one or more of the blades can be removed and replaced with new ones, and thus the main object of my invention is attained, all that is necessary prior to the removal of any one or more of the blades being the withdrawal of one or both of the collars G G, so as to permit the sliding out of the blade from the hub.

I claim as my inVention- The combination, substantially as described, of the flanges E and dovetailed ribs 0 of the blades with the grooved hub and its detachable collars G G, having annular lips h adapted to the flanges of the blades, as set forth.

In testimony whereofI have signed my name to this specification in the presence of two sub scribing witnesses.

Witnesses GEORGE L. MGGAY.

ALFRED L. GRISWOLD, JOHN B. MCGAY, Jr. 

